Investigation on the preferred thermal properties of sleeping bag and indoor environment for preschool-aged children: Towards sleeping thermal comfort

There are differences in thermal perceptions between preschool children and adults, scientific guidance for adults on dressing children is thus essential. This study aimed to find the preferred thermal properties, i.e., thickness and thermal conductivity, of sleeping bag for children to achieve sleeping thermal comfort based on analysis of heat transfer. A validated 3D heat transfer model was established for the analysis. The results showed that skin temperatures (Tsk) at central body segments are higher than those at distal segments. Tsk is positively (p < 0.1) related to fabric thickness and air temperature. Fabric thickness has a stronger influence on Tsk than thermal conductivity. Regression equations expressing relation between Tsk and fabric thickness, thermal conductivity and air temperature were proposed. The matching relation between sleeping bags (thickness being 0.6-5.6 mm and thermal conductivity being 0.06-0.09 W/(m & sdot;K)) on market and indoor air temperature was suggested by solving regression equations in terms of maintaining mean Tsk in a comfortable zone. This study enhanced the understanding of heat transfer of sleeping children. The results would help engineers develop sleeping bag for children, and guide adults to choose appropriate sleeping bag according to indoor temperature, thus saving potential energy consumption caused by air temperature adjustments.